December 2017 Climate Forecast Discussion
December 2017 Climate Forecast Discussion for Jan-Mar through Appr-Jun
The SST forecast shows moderate La Nina conditions for Jan-Mar and Feb-Apr, becoming weak for Mar-May and cool-neutral by Apr-Jun. Most of the subtropical and extratropical North Pacific and North Atlantic SST, and the SST in some other extratropical regions is predicted to be above average during all four forecast seasons, with the exception of the very high latitude South Pacific and Atlantic waters, which become increasingly below average. A very slightly positive Indian Ocean Dipole is predicted for Jan-Mar, dissipating for the later seasons. Slightly above-average north tropical Atlantic SST is predicted for Jan-Mar, followed by near-average SST in the tropical Atlantic for the following three running seasons.
Enhanced probabilities for below-normal precipitation are predicted for Mexico and parts of the southeastern and/or southwestern U.S., as well as part of mainly northeastern or southeastern South America, from Jan-Mar through Mar-May. A weak tilt of the odds toward below-normal is also predicted for central southeast Asia for Jan-Mar through Apr-Jun, for central Chile for Mar-May and Apr-Jun, and for part of eastern China for Jan-Mar through Mar-May. Enhanced chances for above-normal precipitation are forecast for most of Indonesia, the Philippines, part of southeast Asia and northern Australia during most of the period from Jan-Mar to Apr-Jun, and for northern South America from Jan-Mar through Mar-May. A tilt toward above-normal is also predicted for northern Europe for Jan-Mar, and northern Asia for Jan-Mar through Mar-May.
Enhanced probabilities for above-normal temperature are predicted for much of Asia, northern Mexico/southern U.S., and Greenland from Jan-Mar through Apr-Jun. A tilt toward above-normal holds also for parts of Australia for Jan-Mar and most of North America for Mar-May and Apr-Jun. Throughout the globe, the extent and strength of the above-normal tendency is greatest during Mar-May. A tendency toward below-normal temperature is forecast in varying small portions of northern Eurasia and northern South America from Jan-Mar through Mar-May, in northwestern North America for Jan-Mar and Feb-Apr, and in southeast Asia in Apr-Jun. An enhanced likelihood for near-normal temperature is predicted for parts of central Africa and northern South America from Jan-Mar through Apr-Jun, and for Indonesia and part of southeast Asia from Feb-Apr to Apr-Jun.
Citation
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